Dual mode digital trunk card that is used for a T1 24 channel interface or an ISDN PRI 23 B+D interface. The T1/PRI card can be used to connect the telephone system to a carrier provided T1 or PRI trunk for telephone service or it can be used to interconnect two iDCS 100 or 500 telephone systems via a leased point-to-point T1 to create a private network. When used in this fashion, both telephone systems are integrated and can share resources such as a centralized operator, voice mail, etc.
Each voice channel can be configured for direct inward dial (DID), loop start, ground start, or E&M trunks.

Requirements for the iDCS 100 telephone system:

• Maximum one per system
• iDCS 100 3×1 Expansion Cabinet or iDCS 100 2×2 Expansion Cabinet
• CSU or equipment that provides CSU functionality